Drill bit nozzle



April 9, 1963 W. E. SCARBOROUG H ATTOHNEYJ April 9, 1963 w. E.scARBoRouGH 3,084,751

DRILL BIT'NOZZLE Original Filed July 24, 1957 2 Sheets-Sheet 2 W////0mE. Jaa/'o/az/g INVENTOR 3,084,751 DRILL BIT NZZLE William E.Scarborough, Houston, Tex., assigner, by mesne assignments, to DresserIndustries, Inc., Dallas County, Tex., a corporation of DelawareContinuation or' application Ser. No. 673,923, July 24, 1957. Thisapplication Apr. 29, 1%0, Ser. No. 25,623 2 Claims. (Cl. 175-34iti) Thisinvention relates to bits for boring earth formations and moreparticularly to nozzles in those bits with which drilling fluid isjetted downwardly toward the cutting operation carried on -by thecutters against the bottom of the hole. Even more particularly, theinvention relates to the provision of a iiuid nozzle for the drillingfluid which may be easily installed, or replaced by a nozzle ofdifferent size or internal contour.

The bit to which the invention relates may be of any conventional formwherein the drilling fluid is pumped to the bit for direction by anozzle downwardly from the bit. It is customary to provide a nozzlestructure which is of different material than that used for the body ofthe bit itself. The nozzle is usually of material which is highlyresistant to wear such as cast tungsten carbide, sintered carbide or aceramic material. The diiculty solved by the present invention has beenfound in securing such nozzles in place by welding, brazing, cementing,etc. A well-equipped shop has been necessary, in the past, to installnozzles secured by these methods.

The present invention provides a structure which enables nozzles to beeasily installed in the eld. Replacement of nozzles made under theteachings of the present invention may be made with relative ease. Anozzle may thus be readily selected from among various sizes in orderthat a bit be readily adapted to properly utilize the hydraulic capacityof the drilling rig.

Replaceable nozzles have been developed in they past. These nozzles havebeen retained in a fluid discharge bore in the bit body by abuttingtheir upper ends against shoulders in the bore and then inserting snaprings into grooves at the lower end ofthe nozzle. The drilling fluid isvery abrasive, and the exposure of the snap ring as well as the bit bodyat the lower end of the nozzle adjacent the snap ring groove `to thewash of the drilling fluid has caused this snap ring as well as the bodyportion supporting it to erode and fail, permitting the nozzle to belost into the bottom of `the hole. This structural arrangement, whereinthe snap ring and its support are continually exposed to drilling iluid,together with the fact that higher drilling iluid jet velocities andconsequently high pressure differentials across the nozzle are beingused, combine to make the snap ring somewhat unsatisfactory in manycases for retaining nozzles in the bit body. The present inventionprovides a retaining and sealing structure for `a drilling bit nozzlewhich is protected from the abrasive drilling lluid through the bit andwhich is arranged to utilize the resistance to shear of a body membereasily inserted and extracted with common tools from the externalsurface of the bit body.

A main object of the invention is to provide a nozzle for a well drillbit which may be easily installed or replaced through the use ofstructure including a solid retainer member inserted and extracted fromoutside of the bit body and held in shear by forces on the nozzle whenin operative position.

Another object is to provide a retaining structure for a nozzle in adrill bit including a solid deformable body held in shear as it bridgesbetween recesses in the nozzle and bit body, isolated from the abrasiveaction of drilling liuid flowing through the nozzle.

Another object is to provide a retaining structure for a nozzledirecting the drilling fluid of a drill bit downward, including aretainer member structure inserted from outside the bit body and into apassageway bridging between the nozzle and body between the ends of thenozzle. The passageway and pin are sealed from the high pressuredrilling iluid coming to the nozzle from above and the retainingstructure is shielded from the abrasive drilling fluid after it isdischarged from the nozzle.

Other objects, features and advantages of the invention will be apparentto one skilled in the art upon consideration of the specification,appended claims and attached drawings, wherein:

FIG. l is a view in vertical cross-section through a well drill bit andreplaceable nozzle constructed in accordance with this invention;

I FIG. 2 is a view in vertical cross-section through the part of FIG. 1in which the replaceable nozzle is held in operative position;

FIGS. 3 and 4 are cross-sections through the nozzle and bit of FIGS. land 2 showing `different forms for retaining members;

FIG. 5 is similar to FIG. 2, being in vertical crosssection through aportion of the bit, but illustrates another embodiment of the invention;

FIG. 6 is similar to FIG. 2, but illustrates another embodiment of theinvention; and

FIG. 7 is a vertical cross-section through a bit portion in which anozzle of distinctive form is retained in the bit with structureutilizing features of the invention.

In FIG. l of the drawings, a drill bit of the rolling cutter type isillustrated as comprising a head I having downwardly extending legs 2within which the rolling cutters 3 have an arrangement which is wellknown. The head 1 has a dome 4 through which extend one or more passages5 communicating between the interior and exterior of the bit head forthe flow of drilling iiuid which emerges from the passage by way ofnozzle 6, made of erosion resistant mate-rial such as tungsten carbide,sintered carbide, rubber or ceramic material.

Nozzle y6 is shown in 'greater detail in FIG. 2. It is to be understoodthat the invention may also be utilized with other types of bits and isnot limited to the rolling cutter type shown. Further, the inventioncomprehends the use of either a single liuid passage in the bit orplurality of passages in which nozzles are to be positioned to directdrilling iiuid. Fur-ther, the invention comprebends the use of nozzlesin body passages which direct the drilling iiuid in jets against eitherthe cutters or against the bottom or sides of the hole being drilled bythe cutters.

Passage 5 is counterbored to form a shoulder 7 which faces downwardlyand to which the upper end of the nozzle is adjacent. The internaldiameter of the counterbore is slightly larger than the outer diameterof the nozzle in order that the nozzle may be readily .slid into thecoun-terbore, or removed, without rotation.

The nozzle 6 is releasably secured within the counterbore of passage `5by means of a peripheral groove 8 formed in the wall of the `counterboreand a matching groove 9 formed in the external -wall of the nozzleforming a passageway in-to rwhich a retainer member is forced to bridgeacross the grooves. The axis of this passageway 8, 9 is circular, aboutthe nozzle. Retainer member 10, as an elongated solid body, is forcedalong the axis of this passage and thereby deformed, or distorted, int-othe shape of the passage. The retainer member is forced into passageway8, 9 from a passageway 11 through the body of the bit. This passageway11 extends from the external surface of the bit and is brought intopassageway 8, 9 tangentiallly. The registration of these passageways inthis manner enables the retainer member to slide around 8, 9 smoothly inlocking the nozzle into the bit body.

FIGS. 3 and 4 show the relation between the locking passageways andretainer member most clearly. These views are sections taken throughthat portion of the bit holding the nozzle and in a plane common to thepassageway and retainer member. lFIG. 3 shows the retainer member in asolid cylindrical form which can be a nail or the like, while FIG. 4shows a erinkled, wavy, or wiggly form 10A. Both forms have a head whichis driven below `the bit body surface into counterbore 12 on theexternal end of passageway 11. A simple grasping tool, such as pliers,can be used to extract the retainer member manually. A hammer will drivethe retainer member into locking position.

The crinkled retainer member 10A is more easily forced into passageway11 than the solid -form of FIG. 3. This wavy form will permit use ofmetals for retainer member 16A which, in the solid `formt of FIG. 3would prove too brittle to deform into the circular path formed by 8, 9.

Retainer member 10 must be made of substantially nonresilient materialwhich can be deformed into passageway S, 9 but which is tough and strongenough to hold the nozzle against the forces placed on it. In positionwithin its passageway, the body of the retainer member is placed inshear along its entire length. The wiggly form of retainer member `10Ais also placed in shear Within its passageway, but not continuouslyalong its length. The choice of for-m and material for this retainermember depends upon the `subjective factors of a particular designproblem to which -the invention is applied. However, with the materialsnormally available at present, the solid, continuous form of theretainer member of lFIG. 3 offers greater resistance to the shearIforces than the crinkled form because more of its material is placed inshear.

The force of the large pressure drop across the nozzle will, of course,tend to drive iluid between the outer cylindrical surface of the nozzleand the wall of -the counterbore `of passageS. `If the highly abrasivedrilling uid were allowed to wash down between these two surfaces, itwould erode the locking structure and cause its evenftual failure. If aseal were effected between Ithe nozzle and counterbore at a point belowthe retainer member 10, drilling iluid could still flow between thenozzle and counterbore and then out retainer member passage 11 unlessthe latter were sealed. Sealing of passage 11 complicates the use of thebit. Therefore, itt is simpler to provide the seal above the lockingstructure and thus isolate and protect it from the abrasion `of thedrilling huid. The specific form of seal structure utilized in thepreferred embodiment of the invention includes an annular groove aboutthe nozzle, in the bit body passage, and resilient seal body in thegroove to bear against the nozzle surface to provide resistance toleakage.

IFIGS. l and 2 show sealing groove 13 in the wall of the counterbore ofpassage 5 in the bit body, above the locking structure. Seal ring 114 isarranged in groove 13 and compressed against the nozzle lto form theseal. Seal ring 14 is of deformable material such as rubber and normallyhas an oval or circular radial cross-section. It is to be understoodthat seal ring 14 may be of any suitable ilexible deformable materialand that the dimensions of the 4ring with relation -to the groove 13 issuch that the ring 4is under initial compression when installed in thegroove and the nozzle is in position within the counterbore of passage5.

Referring to FIG. 3, it will Ibe seen that when the straight retainermember or pin lll is inserted through passageway or counterbore 11 -tobe driven into position, its inner end will Contact the bit :body at apoint along the Wall of passageway portion 8. At a point (called hereina fulcrum point) spaced from the point of contact of its inner end `andtoward its outer end, the retainer member will contact the nozzle and ata point still closer to the nozzle can move back to a centered position.

the -outer end of the retainer member, it will again contact the bitbody. Of course, the two points of contact with the bit body are on theside of the retainer member opposite `the point of contact with thenozzle. Thus, the retainer member is similar to a ulcrumed lever. As-the retainer -member is driven into position, it pushes the nozzlelaterally 'away from the `fulcrurn point, thereby increasing theclearance between the nozzle and the wall of passage 5 in the vicinityof .the `fulcrum point. This increased clearance is maintained as theretainer member is driven toward its :fully inserted position. As aresult, it is possible within manufacturing tolerances, that theclearance is so great that the seal ring d4 loses its effectiveness onone side of the nozzle, namely, on the side of the fulcrum point. Also,the increased clearance may be great enough that at high pressuredifferentials across the nozzle and hence across the seal ring, thelatter may be extruded into the clearance so as to destroy its sealingability.

In order that the nozzle can be re-centered after the retainer memberhas been driven into position, counterbore 11 is given a lateraldimension in the plane of line 3-3 of FIG. l such that the retainermember as a whole can be rotated about the longitudinal axis of thenozzle suificiently that the nozzle is free to move bacii to a positioncoaxial with passage 5. Stated in another manner, the head of theretainer member would move upwardly in FIG. 3 in an are about the nozzleaxis. As a result, the fulcruming action of the retainer member tendingto hold the nozzle to one side, is removed so that In fact, once thefulcruming action is removed, the natural resiliency of the seal ringwill re-center the nozzle, thereby re-establishing the maximum sealingefhciency of the rmg.

The exact lateral dimension required in counterbore 11 to permitrecentering of the nozzle will be dependent upon a number of designfactors such as the relative diameters of the retainer member andpassageway 8, 9, etc. but the dimensions can be determined by a routinedesigner lfor any particular bit.

FIG. 5 illustrates how a seal groove 15 can be periphorally formed in anozzle. Seal ring 14 can be arranged in nozzle groove 15. rl`he resultis to bring the seal ring up against the surface of the passage in thebit body in a sealing function similar to that produced by bringing theseal ring up against the external surface of nozzle 6 in FIGS. l and 2.

The shoulder provided by the counterbore of passage 5 in FIGS. l and 2is aligned with the nozzle bore to give a smooth ow of drilling fluidfrom the body and into `the nozzle. The nozzle need not abut theshoulder in the sense of performing a sealing function with it. The sealstructure between the upper end of the nozzle and the locking structureperforms this function. Further, the two members need not abut toprevent movement of the nozzle because the locking structure preventsmovement of the nozzle in either direction. I-Iowever, the stream offluid is guided smoothly into the nozzle by properly sizing the nozzleand body passages so they align and the shoulder 7 helps preventerosionof the bit body in the passage 5 adjacent the upper end Vof thenozzle.

In FIG. 5, it is to be noted that the nozzle 16 is fixed in operableposition within a body passage 17 which has no counterbore `to provide aprotecting shoulder at the upper end of nozzle 16. While present daynozzle manufacturing techniques and materials make it desirable that thewalls of the nozzle at its upper end have some thickness (ie. terminatein a shoulder although it can be a rounded one and not terminate in athin edge), it has been found that erosion of the bit body adjacent theupper end of the nozzle is usually negligible even in the absence of theprotecting shoulder. Hence the shoulder can be eliminated and the use ofmatching grooves which are similar to 8 and 9, along with a retainermember within the passageway so formed, is effective to fix the positionof nozzle 16 in passage 17 against movement in either direction. Thisdisclosure of FIG. 5 emphasizes that the combination of retainer memberand matching grooves in body and nozzle is sufficient -to fix nozzle 16against movement in either direction within passage 17 under the urgingof vforces from either direction Without employment of a shoulderstructure in the passage 17.

Another aspect of the invention is shown in FIG. 6 as providing aplurality of combinations of matching body and nozzle grooves withretainer members deformed into them. As shown in FIG. 6, -the nozzle ofthe FIGS. l and 2 has been modified to form a passage retainer membercombination 18, similar to that in which body passageway 11 is included.The result is a series of locking structures for nozzles in passages ofbit bodies. A number of locking means may be utilized as required, underthe teachings of the invention, to resist any anticipated value of shearimposed upon the retainer member by the forces developed across the bitbody passage in which a nozzle is positioned.

FIG. 7 is utilized to illustrate another form of passage with which aretainer member also acts to fix a nozzle into position within a bitbody passage. A bit body portion 2) has been illustrated in verticalcross-section, as well as a nozzle 21 in a passage 22. Passage 22 hasbeen counterbored to provide a shoulder 23 against which nozzle 21 iscaused to abut. A groove 24 has been formed peripherally about nozzle 21in the material of body 20 below shoulder 23. Within groove 24 isarranged an O-ring seal 25 compressed against the external wall ofnozzle 21.

The external surface of nozzle 21 has been reduced in diameter below itsseal structure at 24, 25 to form a shoulder 26. With the top of nozzle21 abutting shoulder 23, nozzle shoulder 26 is caused to register withthe top of a groove 27 formed in lthe wall of the counterbore of passage22. A retainer member 28 is forced Iinto the space formed by groove 27and the space under shoulder 26 of nozzle 21. It is clear that nozzle 21is thus held in abutment against body shoulder 23 by the resistance ofretainer member 28 to the shear force exerted by shoulder 26. The resultis a positional location of nozzle 21, or a locking thereof, within thecounterbore of passage 22.

One advantage of the FIG. 7 arrangement lies in the fact :that thepositional locking provision has been obtained with a relatively cheaperform `for nozzle 21. Thus, a finite amount of valuable nozzle materialis saved by the simple extension of the reduced diameter of the nozzlethe remainder of its length below shoulder 26. The wear resistantmaterials of which Ithese nozzles must be formed is quite expensive, andany saving of this material becomes quite important commercially.

All disclosure of nozzles in the vanious figures of the drawing hasutilized internal configurations in which the internal diameter belowthe top of the nozzle is materially reduced toward the nozzle bottom.These streamlined reductions in cross-section increase the velocity ofthe drilling fluid greatly. However, it must be emphasized that theseconfigurations are only representative of many variations possible. Forexample, it may be required that the nozzle be simply cylindrical.Whatever the configuration used internally of the nozzle, it must not beconstrued as limiting the scope of invention embodied in the locking andsealing combination disclosed.

From the foregoing, it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the apparatus.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense;

This application is a continuation of my copending application SerialNo. 673,923, filed Iuly 24, 1957.

The invention having been described, what is claimed is:

l. A rotary drill bit including a body having a cutter means mountedthereon and a passage for discharging drilling fluid downwardly from thebody; a replaceable, hard, brittle nozzle of circular cross-sectionadapted to be slipped upwardly into the body passage for controlling thedischarge of fluid from the body; a circumferential groove in the outerwall of the nozzle; a circumferential groove in the inner wall of thebody passage surrounding the nozzle and spaced vertically in the bodypassage to match the circumferential groove in the nozzle so that thebody and nozzle grooves together form a first passageway whose walls arelongitudinally divided between the nozzle and body; a second passagewayextending from the exterior of the body to the first passageway; anelongate, stiff, bendable but non-resilient retainer member havingportions thereof disposed in the first and second passageways with theportion in the rst passageway bridging between the grooves in the nozzleand body and preventing endwise displacement of the nozzle from thebody; the nozzle and body grooves and the retainer member portiontherein being vertically spaced `below the upper end of the nozzle andsufhciently far above the lower end of the nozzle that they are isolatedfrom impingement by turbulent drilling fluid with abrasive particlestherein Which is discharged from the nozzle; and a resilient fluidenergized seal means of the 0- ring type between the nozzle and bodyabove the nozzle and body grooves preventing drilling fiuid from fiowingdownwardly between the nozzle and body; said second passageway having alateral dimension sufficiently larger than the corresponding lateraldimension of the retainer member portion in the second passageway suchthat the retainer member can be rotated about the longitudinal axis ofthe nozzle to eliminate the fulcruming action exerted on the nozzle bythe retainer member as the latter is driven into place, therebypermitting the nozzle to be recentered in the body passage by the sealmeans.

v2. A rotary drill bit including a body having a cutter means mountedthereon and a passage for discharging drilling fluid downwardly from thebody; a replaceable, hard, brittle nozzle of circular cross-sectionadapted to be slipped upwardly into the body passage for controlling thedischarge of fluid from the body; a circumferential groove in the outerwall of the nozzle, a circumferential fgroove in the inner wall of thebody passage surrounding the nozzle and spaced vertically in the bodypassage to match the circumferential groove in the nozzle so that thebody and nozzle grooves together form a yfirst passageway whose wallsare longitudinally divided between the nozzle and body; a counterboreextending from the exterior of the body to the `first passageway; ametal retaining member of stiff, bendable but non-resilient material andhaving portions thereof disposed in the first passageway and in thecounterbore with the portion in the first passageway bridging betweenthe grooves in the nozzle and body and preventing endwise displacementof the nozzle from the body; the nozzle and body grooves and the pintherein being vertically spaced below the upper end of the nozzle andsufficiently far above the lower end of the nozzle that they areisolated from impingement by turbulent drilling fiuid with abrasiveparticles therein which is discharged from the nozzle; and an O-ringseal between the nozzle and body above the nozzle and body groovespreventing drilling uid from owing downwardly between the nozzle andbody; said counterbore being of suiiciently larger diameter than that ofthe pin portion disposed therein such that the pin, after being driveninto place, can be rotated about the nozzle axis to eliminate thefulcrurning action of the pin on the nozzle, thereby permitting thenozzle to be recentered in the body passage by the O-ring.

References Cited in the le-of this patent UNITED STATES PATENTS Mackeyet al Feb. 28, 1933 Howard et al Apr. 13, 1937 Melsonl Feb. 9, 1943Mahoney Jan. 1l, 1949 Payne Oct. 7, 1958 Hammer May 5, 1959 Sherman Dec.8, 1959

1. A ROTARY DRILL BIT INCLUDING A BODY HAVING A CUTTER MEANS MOUNTEDTHEREON AND A PASSAGE FOR DISCHARGING DRILLING FLUID DOWNWARDLY FROM THEBODY; A REPLACEABLE, HARD, BRITTLE NOZZLE OF CIRCULAR CROSS-SECTIONADAPTED TO BE SLIPPED UPWARDLY INTO THE BODY PASSAGE FOR CONTROLLING THEDISCHARGE OF FLUID FROM THE BODY; A CIRCUMFERENTIAL GROOVE IN THE OUTERWALL OF THE NOZZLE; A CIRCUMFERENTIAL GROOVE IN THE INNER WALL OF THEBODY PASSAGE SURROUNDING THE NOZZLE AND SPACED VERTICALLY IN THE BODYPASSAGE TO MATCH THE CIRCUMFERENTIAL GROOVE IN THE NOZZLE SO THAT THEBODY AND NOZZLE GROOVES TOGETHER FORM A FIRST PASSAGEWAY WHOSE WALLS ARELONGITUDINALLY DIVIDED BETWEEN THE NOZZLE AND BODY; A SECOND PASSAGEWAYEXTENDING FROM THE EXTERIOR OF THE BODY TO THE FIRST PASSAGEWAY; ANELONGATE, STIFF, BENDABLE BUT NON-RESILIENT RETAINER MEMBER HAVINGPORTIONS THEREOF DISPOSED IN THE FIRST AND SECOND PASSAGEWAYS WITH THEPORTION IN THE FIRST PASSAGEWAY BRIDGING BETWEEN THE GROOVES IN THENOZZLE AND BODY AND PREVENTING ENDWISE DISPLACEMENT OF THE NOZZLE FROMTHE BODY; THE NOZZLE AND BODY GROOVES AND THE RETAINER MEMBER PORTIONTHEREIN BEING VERTICALLY SPACED BELOW THE UPPER END OF THE NOZZLE ANDSUFFICIENTLY FAR ABOVE THE LOWER END OF THE NOZZLE THAT THEY AREISOLATED FROM IMPINGEMENT BY TURBULENT DRILLING FLUID WITH ABRASIVEPARTICLES THEREIN WHICH IS DISCHARGED FROM THE NOZZLE; AND A RESILIENTFLUID ENERGIZED SEAL MEANS OF THE ORING TYPE BETWEEN THE NOZZLE AND BODYABOVE THE NOZZLE AND BODY GROOVES PREVENTING DRILLING FLUID FROM FLOWINGDOWNWARDLY BETWEEN THE NOZZLE AND BODY; SAID SECOND PASSAGEWAY HAVING ALATERAL DIMENSION SUFFICIENTLY LARGER THAN THE CORRESPONDING LATERALDIMENSION OF THE RETAINER MEMBER PORTION IN THE SECOND PASSAGEWAY SUCHTHAT THE RETAINER MEMBER CAN BE ROTATED ABOUT THE LONGITUDINAL AXIS OFTHE NOZZLE TO ELIMINATE THE FULCRUMING ACTION EXERTED ON THE NOZZLE BYTHE RETAINER MEMBER AS THE LATTER IS DRIVEN INTO PLACE, THEREBYPERMITTING THE NOZZLE TO BE RECENTERED IN THE BODY PASSAGE BY THE SEALMEANS.